Electronic thermometers are becoming increasingly more attractive as their cost decreases. Although their initial cost may be relatively high, the cost over their extended period of use is comparable to that of mercury thermometers, especially when the electronic thermometers are used with disposable probe covers and the cost of repeated sterilization and breakage allowances for mercury thermometers is considered. Some electronic thermometers employ circuitry similar to digital volt meters which is neither the best suited nor most inexpensive approach for implementing thermometer systems. Thermometer systems, especially those used in patient care, require only limited range capability which admits of much simplification relative to broader range systems and renders redundant many circuits used in such instances.
Recent advances, U.S. Pat. No. 3,940,595, have achieved a measure of success in reducing the number of counters and reducing costs. However, the substituted structure is still fairly complex and expensive.